what-is-acp

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

There are no annotations, so the description carries the burden of disclosing behavior. It describes the tool as a 'Lesson,' implying informational and read-only behavior. However, it does not explicitly state that there are no side effects or what action occurs when invoked (e.g., showing text or marking a lesson complete). The nature is clear enough for an informational tool, but a bit more explicitness would improve transparency.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is two sentences, front-loaded with the lesson identifier. The second sentence provides precise subject matter and relational context. Every sentence is informative with no redundancy or filler.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given the tool's simplicity (no parameters, no output schema, no annotations), the description covers the essential topic and relationship between ACP and AP2. It does not describe the exact output or how the lesson is presented, but for a curriculum lesson tool, the stated content scope is sufficient. It could be more complete by mentioning the lesson's outcome, but the current description is adequate for selection and invocation.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The tool has zero parameters and the schema coverage is 100% (empty schema). Per the rubric, a baseline of 4 is assigned for 0 parameters. The description adds no parameter details because none exist, and that is appropriate.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly identifies the tool as a curriculum lesson ('Lesson 14') and names the exact subject: ACP (Agent Commerce Protocol) from OpenAI/Stripe. It further specifies the lesson's scope ('How ACP and AP2 relate, when each applies'), which distinguishes it from sibling tools like what-is-ap2 and what-is-x402.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description states 'when each applies,' providing guidance on when to use this lesson versus AP2-related content. It does not explicitly name alternative tools or state 'use this when...' as a direct exclusion, but the context is clear enough for an agent to select this tool when learning about ACP and its applicability.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.